Cisco Technology, Inc.

Nobushige Akiya

Carlos M Pignataro

Nagendra Kumar Nainar

James Neil Guichard

Paul M Quinn

George Swallow

David Delano Ward

Sami Boutros

Muthurajah Sivabalan

Tarek Saad

Nagendra Kumar

Matthew Balint

Srihari Raghavan

Douglas Wooff

Mallik Mudigonda

In one embodiment, a system and method are disclosed for sending a request and receiving a reply. The request contains a network service header including a flow label field and a target index field. The flow label field contains a set of available flow labels. The target index field includes a value indicating a target node. The reply contains information indicating which of the flow labels can be used to route a packet to each of the next hop nodes downstream from the device that sent the reply. This process can be repeated for other nodes on a path, and other paths in a service topology layer. The information determined by this process can be used to perform other necessary functionalities at the service topology layer.

Multi-path aware tracing and probing functionality at service topology layer

In one embodiment, a method includes assigning a discriminator to a target in communication with a reflector at a network device, identifying at the reflector, a packet comprising the discriminator, the packet transmitted from an initiator in a seamless bidirectional forwarding detection (S-BFD) session, and transmitting a response packet from the reflector to the initiator. The response packet includes information for the target obtained by the reflector through monitoring of the target. The target may comprise a plurality of entities. An apparatus and logic are also disclosed herein.

Monitoring through S-BFD (seamless bidirectional forwarding detection)

In one embodiment, a method includes identifying a failure of a service function at a service node in a service chain, receiving a packet at the service node, and processing the packet at the service node according to a flag associated with the service function and set based on a criticality of the service function. An apparatus is also disclosed herein.

Selective service bypass in service function chaining

An example method for seamless path monitoring and rapid fault isolation using bidirectional forwarding detection (BFD) in a network environment is provided and includes determining a BFD target identifier type for communicating in a BFD session in a network environment, determining a non-zero globally assigned BFD discriminator value associated with the BFD target identifier type, populating a Your Discriminator field in a BFD Control Packet with the non-zero globally assigned BFD discriminator value, with a My Discriminator field in the BFD Control Packet being populated with a locally assigned BFD Discriminator value, and initiating the BFD session by transmitting the BFD Control Packet to a target node in the network. In a specific embodiment, the BFD target identifier type is type 3, and the non-zero globally assigned BFD discriminator is an Alert Discriminator reserved by substantially all nodes in the network exclusively for BFD traceroute operations.

Seamless path monitoring and rapid fault isolation using bidirectional forwarding detection in a network environment

In one embodiment, a method includes generating a path validation packet at a network device, the path validation packet including a plurality of segment identifiers for use in segment routing and an operations, administration, and management (OAM) segment identifier for use in path validation, transmitting from the network device the path validation packet on a path having a plurality of routers associated with the segment identifiers, one of the routers associated with the OAM segment identifier, and validating the path if a return path validation packet is received. An apparatus is also disclosed herein.

Path validation in segment routing networks

The present disclosure provides for carrying downstream mapping information in an echo request message and/or echo reply message, which can describe both IP (Internet Protocol) multipath information and label multipath information. A transit node (e.g., an LSR element) that receives an echo request message from an initiator node determines downstream mapping information, which is returned to the initiator node. Transit node determines whether a newly defined type of multipath information (type 10) should be generated to return the downstream mapping information, based on whether transit node performs load balancing based on labels or IP header information, and whether transit node imposes entropy labels. A multipath information type 10 element includes either IP multipath information or label multipath information, as well as associated label multipath information that includes one or more entropy labels that map to the IP or label multipath information being returned.

LSP ping/trace over MPLS networks using entropy labels

In one embodiment, a Bidirectional Forwarding Detection (BFD) asynchronous mode session is established between two packet switching devices interconnected by one or more physical links. Prior to L2 or L3 services being established, each of these packet switching devices does not know the Media Access Control (MAC) nor Internet Protocol (IP) addresses of each interface of the other packet switching device that is connected to one of these link(s). A request to establish a BFD session is sent from one packet switching device to the other, with a MAC frame including the request being addressed to a group, broadcast, or other address that the receiving packet switching device will recognize and thus process the received request. Based on information contained in this received MAC frame, the receiving packet switching device has the information it needs, and sends a BFD control frame to the other packet switching device.

Establishing a bidirectional forwarding detection (BFD) asynchronous mode session without knowing a Prior layer-2 or layer-3 information

A method for software loading and initialization in a distributed network of nodes. A master node provides a node information database and a software package database. A node performing an initial boot requests a boot image and software package download from the master node. The master node finds the node's software configuration information in the node information database and sends the boot image and software packages to the node from the software package database. The node reboots into the boot image and verifies the software versions with the master node. If the node has the correct software, then it completes the boot sequence, otherwise, the master node sends the correct software packages to the node which then continues with the boot sequence.

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Kanata, Canada

Nobushige Akiya